Look at the inches side of your tape measure. The hash marks between 1-inch increments come in four different lengths. The longest, which is centered, represents 1/2 inch. The second longest, of which there are two, represent 1/4 inch and 3/4 inch. The third longest, of which there are four, represent 1/8, 3/8, 5/8 and 7/8 inch. The smallest hash marks each indicate 1/16 inch.
Simplify fractions when measuring to make your tape measure easier to use. For example, instead of marking down a measurement as "14/16," mark it as "7/8." The varying lengths of the hash marks make it easier to keep track of each fraction.
Flip your tape measure to the centimeter side. The hash marks between centimeters each indicate 1/10 centimeter, with a longer one in the middle to indicate the 1/2 centimeter mark.